如何让一个页面电脑和手机显示不同的广告

<script>
var url = location.search;
url = url.substr(1);
var bs={
versions:function(){
var u = navigator.userAgent, app = navigator.appVersion;
return {
trident: u.indexOf('Trident') > -1, 
presto: u.indexOf('Presto') > -1,
webKit: u.indexOf('AppleWebKit') > -1, 
gecko: u.indexOf('Gecko') > -1 && u.indexOf('KHTML') == -1, 
mobile: !!u.match(/AppleWebKit.*Mobile.*/)||!!u.match(/AppleWebKit/), 
ios: !!u.match(/\(i[^;]+;( U;)? CPU.+Mac OS X/), 
android: u.indexOf('Android') > -1 || u.indexOf('Linux') > -1, 
iPhone: u.indexOf('iPhone') > -1,
iPad: u.indexOf('iPad') > -1         
};
}(),
language:(navigator.browserLanguage || navigator.language).toLowerCase()
} 
var flag = true;
if(bs.versions.mobile && url!='mobile'){
if(bs.versions.android||bs.versions.iPhone||bs.versions.iPad||bs.versions.ios){
flag=false;
}
}
if(flag){
/*940*90电影网广告位*/
var cpro_id = "u3191574";  
document.write("<script src='//cpro.baidustatic.com/cpro/ui/c.js' type='text/javascript'></sc"+"ript>");
}else{
/*20:6 信息流 2018/6/22*/
var cpro_id = "u3466360";
document.write("<script src='//cpro.baidustatic.com/cpro/ui/cm.js' type='text/javascript'></sc"+"ript>");
}
</script>

第二种：

<style type="text/css">
.pc_acmsd{display:block;}
.m_acmsd{ display:none}
@media(max-width:768px) {
.pc_acmsd{display:none !important;}
.m_acmsd{display:block !important;}}
</style>
<div class="pc_acmsd">此处放入显示在电脑上的广告代码</div>
<div class="m_acmsd">此处放入显示在手机上的广告代码</div>